Here's a figure for death from infectious disease by the CDC - note that antibiotics don't appreciably change the rate in decline
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm4829a1.htm#fig1
just a random find - this paper from 1902 mentions the debate, too, with some descriptions of 'natural experiments' https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2401255/?page=1
Also, I am not saying that antibiotics and medications don't work - just that the story actually is more interesting than one might initially guess.
Lastly, these data discuss Western populations - I've heard the opposite may be true in poor countries.